WEDNESDAY, April 16, 2014 (HealthDay News) -- The rates of five serious complications from diabetes -- heart disease, stroke, kidney disease, amputations and death -- have all dropped dramatically since 1990, a new U.S. government study shows.

Heart attack rates have decreased nearly 70 percent in people with diabetes. Stroke rates have dropped by more than 50 percent, as have lower extremity amputations. Deaths from high blood sugar crises have fallen nearly 65 percent, and the risk of end-stage kidney disease is down 28 percent, according to the study.

The biggest declines in diabetes-related complications have occurred for heart attack and stroke, especially among people aged 75 and older.

But, the news isn't all good.

During the same time frame that diabetes complications were dropping, the rates of diabetes diagnoses were soaring. In 1990, 6.5 million Americans had diabetes. By 2010, that number was 20.7 million, according to the study authors.

Health experts point to the obesity epidemic as a leading contributor to the rise in cases of type 2 diabetes.

And, although the rates of diabetes complications are significantly lower than they used to be, they're still far greater than for those without diabetes. For example, someone with diabetes has a six times greater risk of developing kidney failure than does someone without the disease. The risk of amputation is 10 times higher, while the risk of a heart attack is twice as high, according to the study.

"In general, this study is good news. Rates of diabetes complications have declined, and that's a testament to what good care and self-management can do," said study author Edward Gregg, chief of the U.S. Centers for Disease Control and Prevention's epidemiology and statistics branch in the division of diabetes translation.

"For the average person with diabetes, the complication risk is far less than it was. But, we wouldn't want to send the message that this battle is won," Gregg added. "The baby boom generation is moving into the high-risk years for diabetes. Even if we make continued improvements, the fact that the baby boom generation is moving into high-incidence years means a lot of cases in the future."

Results of the study are published in the April 17 issue of the New England Journal of Medicine. Data for the research came from the National Health Interview Survey, the National Hospital Discharge Survey, the U.S. Renal Data System, and the U.S. National Vital Statistics System.

In 1990, just over 140,000 Americans with diabetes had a heart attack. In 2000, that number had jumped to 191,000. By 2010, it was down to almost 136,000, according to the study.

A closer look at those heart disease numbers, to see how many people per 10,000 with diabetes had a heart attack, shows a much steadier decline. In 1990, 141 people per 10,000 with diabetes had a heart attack. In 2000, it was 106 people per 10,000, and by 2010 that number had dropped to a low of 45.5 per 10,000 people with diabetes, according to the study.

The only category of complication that didn't see a drop of more than 50 percent was end-stage kidney disease, although there was nearly a 30 percent decline in this complication. Gregg said it's possible that the large drops in the other categories may be slowing down the rates of improvement in kidney disease. People with diabetes may now be living long enough to get end-stage kidney disease, he explained.

Dr. Joel Zonszein is director of the clinical diabetes center at Montefiore Medical Center in New York City. He said the new study "shows us we have an opportunity. Good treatment can prevent diabetes complications. When we treat early and aggressively, people with diabetes -- either type 1 or type 2 -- can do quite well."

Zonszein said he thinks "medical therapy is making a big difference in complications." That includes blood-sugar lowering medications, drugs for high blood pressure and drugs to lower cholesterol levels, he said.

Gregg agreed that better tools to manage risk factors for complications -- such as medications -- along with better ways to identify people with diabetes may have contributed to the improvement in the complication rates. He said diabetes education has also likely played a big role in the drop in complications.

"We need to continue to work on improving care, but we also need to turn more attention to preventing diabetes in the first place," Gregg said.